How Does Peer-Reviewed Scientific Literature Affect Policy Decisions?

Instructional Objectives

Describe what type of source is used to construct reports used by governments to create policy.

Discuss difficulties in monitoring glacier health.

Identify the largest source of uncertainty in future glacier health and what steps are being taken to remedy this uncertainty.

Describe why climate change is a political contentious issue.

Describe the ramifications of stating unverified opinions as scientific facts.

Discuss the utility of assessment reports such as the United Nation’s Intergovernmental Panel on Climate Change Assessment Report.

Content Explanation

Many students, and people in general, do not realize the separation between peer-reviewed scientific literature and scientific facts reported in the popular press. Peer-reviewed articles are published through a formalized process where a submission is revised after being reviewed by external, impartial experts. All parties (the authors, reviewers, and an editor who oversees the review process) approve of the final version before publication in order to ensure accuracy.

Although the content may not be completely correct, uncertainties, extrapolations, and interpretation are clearly stated so that a close reading of the article precludes misconceptions. An article in the popular press, despite an author’s best attempt at accuracy, is not subject to a formal vetting process by topical experts and is thus more likely to include unintentional errors. This lesson examines one incident where an inaccurate statement reported in the popular press was inadvertently included in a peer-reviewed report intended to provide information to policy-makers on a politically contentious issue (climate change and water supply).

Lesson Summary

Students will read articles related to a misstatement of future glacier health in the Himalayas that was reported in the 2007 United Nation’s Intergovernmental Panel on Climate Change Assessment Report 4. The class will discuss the articles and ramifications of inaccuracies in scientific literature as well as the importance of validating sources as peer-reviewed. As this topic is complex, the students will need guidance in the form of an introduction to peer-reviewed literature, which is outlined here. Furthermore, the objective of this lesson is not to vilify the IPCC or any other well-intentioned group, but rather to elucidate the use of proper references and procedure when summarizing a contentious scientific issue with broad geopolitical implications.

Peer-reviewed literature refers to a document that has been reviewed by other subject experts before being published. First, a group of scientists investigates a scientific question using models, lab experiments or observations. After processing data, refining models, or explaining observations, the group proceeds to write a manuscript. This manuscript is then submitted to a journal.

The editor of the journal reads the manuscript, decides if it is suitable for publication in that journal, and selects reviewers external to the work who are experts in the field. The manuscript is then sent to reviewers who make comments, may attempt to replicate the work, identify caveats in the experiment or explanation, and otherwise attempt to constructively criticize the manuscript in order to advance the science. Once the review is complete, and assuming the editor decides not to reject the manuscript based on the review, the comments are submitted to the author who must carefully respond to each before resubmission. This process may iterate several times before all parties are satisfied with the work and it becomes a publication. Although this process is imperfect, it tends to minimize incorrect conclusions, prevent duplicate work, and is generally an efficient manner to advance the science. Included in this process is a clear assessment of what is fact, uncertainties in observations, and what may be interpretation or extrapolation designed to foment creativity in addressing a problem.

Due to the highly technical nature of many scientific topics and the voluminous literature that addresses current research in an active field, synthesis reports are necessary so that policy-makers and the public can become informed and make decisions as needed. Therefore, panels of experts, such as the United Nation’s Intergovernmental Panel on Climate Change (UN IPCC) have an exceedingly important purpose: to shift through peer-reviewed literature, much of which may be in conflict despite the peer-review process, and distill the state of the science into a succinct report. Generally, these reports are well intentioned and the scientists make sincere efforts to give an impartial, perhaps laconic, assessment of the science in a field. Here we report on a singular error in the UN IPCC and the ramifications of such an error as an example of the importance of adhering to established peer-review procedure when giving advice which may be used to formulate policy. In general, the IPCC has provided highly accurate advice on the current state of climate change and made clear that warming is unequivocally due to anthropogenic influences. Furthermore, the statements about projections of future warming, its effects, and mitigation efforts have been valuable to policy-makers worldwide. Perhaps the salient point of this lesson as that one error was made due to a singular oversight in procedure and does not invalidate the body of evidence in this support.

The error examined here is the citation of a popular interview in a document that nominally and truly, except in this case, only cited peer-reviewed literature. We hope that students learn the difference between peer-reviewed and popular literature, learn to read assessment reports and assimilate information quickly, and analyze political implications of scientific problems.

Administrative Considerations

This lesson involves a lot of reading. ESL students may have trouble with comprehension. Students with lower reading comprehension skills may need some guidance. Some of the articles are from peer-reviewed journals and therefore may need to be accessed via libraries with paid. Some of the readings are rather voluminous so content is summarized and especially important sections are identified.